Re: Cherie's '84 Coupe DeVille Project

Now I am worried, how hot did it get? Did it start continue to run for a bit after you turned the key off?
HT4100 + Overheating = Trouble!

When you get it back home pull all the spark plugs, and rent a compression tester (free), and run a compression test, and check the condition of the oil.
I hate to be a pessimist, but it would be best to rule out headgasket issues right away.

Now I am worried, how hot did it get? Did it start continue to run for a bit after you turned the key off?
HT4100 + Overheating = Trouble!

On the straight-a-ways the engine temp was hovering at about 94C and seemed fine. When we started to climb a couple hills, I got a bunch of backfiring, and a loss of power, at that point it was around 105C, and I was worried because that's above boiling temp of water (although it's only 50% water, 50% ethylene glycol). I had to drive about a minute to pull over in a safe spot (Hwy 17 is nasty and narrow), and when I turned off the engine, the temp was reading 114C. After turning the engine off, it was dieseling for about 1 or 2 seconds.

Originally Posted by lacville78

When you get it back home pull all the spark plugs, and rent a compression tester (free), and run a compression test, and check the condition of the oil.
I hate to be a pessimist, but it would be best to rule out headgasket issues right away.

We dropped the car off at a good local shop. It'll be nice to have a fresh pair of eyes check the car over. And I get a small break. I love car work, but man I busted my butt for the last 30 days and I'm exhausted. It feels good to put the Caddy in someone else's hands for a day.

Oh, I'm sure my previous compression readings are irrelevant now, but compression was decent in all cylinders except #5, which was a bit low. Hopefully I stopped the car before any major damage was done. Regardless though, I'm sure some about of damage has been done because it's not good for cars to overheat even once.

Re: Cherie's '84 Coupe DeVille Project

Originally Posted by 1980coupe

No bueno...
Have you thought of maybe swapping engines out, so you won't experience any more problems done the road?

That was my FIRST plan back in early 2012, but California makes it REALLY hard to do engine swaps, and I don't have the extra money to gamble on that kind of thing. I'm hoping someday I'll find out exactly what I would be allowed to put in it (besides a rebuilt ht4100), and finally do a swap on it. I heard wiring harness conversions are part of the trouble too.

Re: Cherie's '84 Coupe DeVille Project

Another concern I have is the condition of the transmission, you mentioned the car not shifting properly, and now there is overheating to consider.
When the engine gets hot, the transmission does as well. Make sure to check the state of the transmission fluid.